// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_BASE_TEST_DATA_STREAM_H_
#define NET_BASE_TEST_DATA_STREAM_H_

#include "net/base/net_export.h"
#include <algorithm>
#include <string.h> // for memcpy().

// This is a class for generating an infinite stream of data which can be
// verified independently to be the correct stream of data.

namespace net {

class NET_EXPORT TestDataStream {
public:
    TestDataStream();

    // Fill |buffer| with |length| bytes of data from the stream.
    void GetBytes(char* buffer, int length);

    // Verify that |buffer| contains the expected next |length| bytes from the
    // stream.  Returns true if correct, false otherwise.
    bool VerifyBytes(const char* buffer, int length);

    // Resets all the data.
    void Reset();

private:
    // If there is no data spilled over from the previous index, advance the
    // index and fill the buffer.
    void AdvanceIndex();

    // Consume data from the spill buffer.
    void Consume(int bytes);

    int index_;
    int bytes_remaining_;
    char buffer_[16];
    char* buffer_ptr_;
};

} // namespace net

#endif // NET_BASE_TEST_DATA_STREAM_H_
